The reference German Patent No. DE 196 20 980 purportedly concerns an audio device for a vehicle where phone conversations are processed using an appropriate voice- or signal-controlled allocation, such that an allocation to the individual engaged in the phone conversation is made, but also in such a way that the positioning is freely defined purely by an intensity control.
The reference German Patent No. DE 43 08 398 purportedly concerns an approach for an active noise reduction system for a passenger compartment of a motor vehicle by diminishing vibrational noises generated by a four-cylinder, four-stroke engine and transmitted to the passenger compartment.
Approaches directed to reducing noise in passenger compartments may create better conditions, both for internal communication within the passenger cell, as well as for external communication from the passenger cell to the outside, for example via radio paging. Such systems may, in fact, be able to reduce disturbing noises, but they are not able to completely compensate for these noises.
Even when engine and driving noises are reduced to the greatest possible extent, the underlying problem of communication within a passenger cell still persists. This is due in part to the seating arrangement within the passenger cell. In order to communicate well, i.e., to be heard clearly, within the passenger cell, particularly in conversations involving individuals in the front as well as in the rear areas of the passenger cell, each person participating in the conversation may oftentimes be forced to change position, posture or even voice volume to be understood in the conversation. This can mean that the driver and front-seat passenger must turn their heads around somewhat to the back and that the rear passengers may have to lean forward somewhat to be able to understand one another clearly. A situation of this kind inevitably can impair the driver's concentration and attentiveness to driving the vehicle, and therefore may compromise the safety of the vehicle's passengers and the vehicle, as well as any other vehicles and/or persons in the general vicinity.
The reference German Patent No. DE 34 131 81 purportedly concerns a large-room acoustic irradiation system for radiating large rooms or open spaces with sound according to principles of amplification or simulation, which is approximately true to time and, to the extent that is necessary, to sound level, of sonic fields propagating from the source via the area of action into the reception area, with a temporal source priority. This means that the acoustic radiators do not radiate until after the wavefronts of the original acoustic sources, i.e., of the acoustic radiator simulating these and of the acoustic radiators closer to the source, have passed, and that the time intervals or the amplifications are differentiated by capacity and type of source. This approach purportedly concerns itself alleviating the contradiction between propagation-delay and amplitude localization, even in transition regions where the first audible acoustic radiator is located, instead of the original sound source, when the comparison is made. Accordingly, the approach appears directed to the source, the area of action, and the acoustic radiator locations, and considers the acoustic capacity of the sources.
The reference European Patent Publication No. 0 712 264 purportedly concerns a multichannel sound reproduction method and apparatus. This reference refers to reproducing multichannel sound programs as adapted programs, but virtually in conformance with the standard.